The University of Pennsylvania’s department of earth and environmental science has been awarded a $4.35 million, five-year grant from the National Science Foundation to establish a Critical Zone Observatory in Puerto Rico. The Luquillo Critical Zone Observatory (LCZO) is one of six observatories established by the NSF. Each of these observatories brings together diverse groups of researchers, educators, and students who study the Critical Zone to provide the scientific basis for its long-term management.

Dr. Frederick Scatena, professor and chair of earth and environmental sciences and one of the LCZO project’s principal investigators, describes the “Critical Zone” as the outer layer of the Earth that directly sustains human life. This zone extends from the top of the vegetation canopy into the underlying bedrock and includes all the physical, chemical and biological processes that shape and transform the Earth’s surface as well as its plant and animal life.

Located in the Luquillo Mountains of northeastern Puerto Rico, the LCZO’s physical infrastructure includes weather stations, instrumented soil pits and riparian (land-stream interface) zones, and stream flow gauges. A multidisciplinary team of geoscientists is working at the site to address how critical zone processes and the flow and transformations of material differ in landscapes with contrasting bedrock but similar climates, land use, and geologic histories. The team will also be exploring the implications of these differences for the long-term sustainability of water and soil resources. Specific research projects at the LCZO include studies of deep weathering, soil formation and soil carbon accumulation, riparian zone dynamics, fluvial geomorphology, and meteorology.

In addition to researchers from Penn, the LCZO will involve collaborators from Pennsylvania State University, the University of California at Berkeley, the University of New Hampshire, the University of Puerto Rico, the US Geological Survey, and the US Forest Service International Institute of Tropical Forestry. The observatory will also provide facilities for collaborators from a host of US and international universities and research centers.

The five other National Critical Zone Observatories are Southern Sierra (University of California at Merced), Shale Hills (Pennsylvania State University), Boulder Creek (University of Colorado), Christina Watershed (University of Delaware and the Stroud Water Resource Center), and Jemez River Basin and Santa Catalina Mountains (University of Arizona).